Rate gyro type corrector for automatic boat steering gear utilizing an aerodynamic surface



May 16, 1967 M. GIANOLI 3,319,594

RATE GYRO TYPE CORRECTOR FOR AUTOMATIC BOAT STEERING GEAR UTILIZING AN AERODYNAMIC SURFACE 4 Sheets-Sheet 1 Filed May 7, 1965 May 16, 1967 M. L. GIANOLI 3,319,594

RATE GYRO TYPE CORRECTOR FOR AUTOMATIC BOAT STEERING GEAR UTILIZING AN AERODYNAMIC SURFACE Flled May 7 1965 4 Sheets-Sheet 2 May 16. 1967 M. L. GIANOLI 3,319,594

RATE GYHQ TYPE CORRECTOR FOR AUTOMATIC BOAT STEERING GEAR UTILIZING AN AERODYNAMIC SURFACE 4 Sheets-Sheet 3 Filed May 7, 1965 M a 5 e w q m w 3m E h T s M. L. GIANOLI RECTOR FOR AUTOMATIC BOA GEAR UTILIZING AN AERODYNAMIC SURF R O C P. Y T w H G 5 1 PM v 6 w 1 M y d e a l 1 M F United States Patent Oilice 3,319,594 Patented May 16, 1967 3,319,594 RATE GYRO TYPE CORRECTOR FOR AUTOMATIC BOAT STEERING GEAR UTILIZING AN AERO- DYNAMIC SURFACE Marcel Louis Gianoli, Neuiily-sur-Seine, France, assignor to Mecanique Navale et Outillage de Precision M.N.0.P., Asnieres, Seine, France Filed May 7, 1965, Ser. No. 454,012 Claims priority, application France May 12, 1964, 974.0?3, Patent 1,403,748 15 Claims. (Cl. 114144) This invention relates to an improvement to the type of automatic boat steering gear which uses, as the sensing energy and motive power, the reactions of the relative wind on aerodynamic surfaces exposed thereto.

Such aerodynamic surfaces may consist either of a conventional wind-vane rotatable about a vertical axis, or of a vane rotatable about a near-horizontal axis, as described in US. patent application Ser. No. 248,635, filed Dec. 31, 1962. I When, following a disturbance, the boat is restored to its initial straight course, such gear sometimes has the disadvantage of allowing the boat to oscillate due to the steering system being ill-adapted to the adjustment conditions.

It is the object of the present invention to overcome this disadvantage and to accordingly provide a rate gyro tylpe corrector for automatic boat steering gear of the type comprising an aerodynamic surface which is exposed to the wind and directly or indirectly connected to the submerged rudder of the boat, the reactions of the wind on said surface generating the sensing energy and motive power required for steering, said corrector comprising a rate gyro which detects deviations of the boat from its course and controls a member for modifying the aerodynamic characteristics of said surface exposed to the wind whereby to generate, for each course deviation, through the resultant modification of said characteristics, a correction upon the submerged rudder resulting in a reduced course deviation and an aperiodic damping. By operating on the member for modifying the aerodynamic characteristics of the surface exposed to the wind, the rate gyro, which is inadequate for actuating the submerged rudder directly, enables said surface to generate the motive power required to correct the submerged rudder.

The choice of a rate gyro as the course deviation detector results in a most successful combination, because this instrument, which is sensitive to the veering rates of the vessel, allows the oscillations to be damped. Further more, being basically simple, it will provide protracted service without going out of adjustment. Finally, it can be maintained operative by the relative wind without recourse to an auxiliary power source, which is a useful feature in the case of boats that are propelled by sails instead of an engine and are consequently ill-equipped to furnish electric power for any extended length of time.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings:

FIGS. 1 and 2 are schematic illustrations of two possible forms of embodiment of a rate gyro type corrector according to the invention, associated to two. difierent embodiments of an aerodynamic surface exposed to the wind.

FIG. 3 is a schematic illustration of an embodiment comprising a leading edge flap.

FIG. 4 is a schematic illustration of an embodiment comprising a spoiler.

FIG. 5 is a schematic illustration of an embodiment comprising a spar positioned at the centre of pressure of the flap.

FIG. 6 is a schematic illustration of an embodiment comprising a secondary fla hinged to the rudder.

FIG. 7 is a schematic illustration of an embodiment comprising an independent rudder.

The form of embodiment shown in FIG. 1 relates to the case of a wind-vane 1 coupled in conventional manner to the rudder helm. This figure represents the case of navigation with a following wind V tending to maintain the sensing wind-vane or aerodynamic surface 1 aligned in its direction. Said aerodynamic surface is rigidly connected to a hollow vertical hub 2 rotatably mounted inside a support 3 adapted to swivel in a base 4 fixed to the deck 5. The hub 2 carries a pinion 6 meshing with a further pinion 7 which is rigid with a vertical shaft 8 mounted on the deck 5 and carrying an arm 9 connected to the rudder 10 through a rod 11.

It will be seen that if the boat veers to the right, the Wind will impinge upon the right-hand side of the windvane 1 and cause it to pivot in the direction of the arrow f while the pinion 7 will rotate in the opposite direction and swivel the arm 9 in the direction of arrow f and the rudder in the direction of F, i.e. in the direction tending to counter the veering movement of the boat to the right.

In accordance with the present invention, there is associated to this classic arrangement a rate gyro consisting of a wheel 12 equipped with blades 13 upon which the wind impinges tangentially, thus causing the wheel to rotate in the direction of the arrow r. The cradle 14 on which this wind turbine is rotatably mounted is adapted to rotate on the support 3, about its shaft 15 which is carried in two brackets 16 which are so mounted on said support as to operate a flexible transmission system 17 mounted in the hollow hub 2 and connected to a flap 18 which is hinged to the trailing edge of the wind-vane 1. The transmission 17 causes the flap 18 to deflect, the effect of which is to modify the reactions of the wind on the windvane.

It will be seen that the direction of rotation of the wheel 12 and the operating sense of the transmission between the wheel 12 and the flap 18 are such that, when the boat veers to the right for example, the resulting gyroscopic precession moment is exerted in the direction of the arrow p, thereby causing the transmission link 17 to be moved downwardly and the flap 18 to be deflected in the direction of the arrow b. This deflection tends to cause the wind-vane 1 to pivot in the direction of the arrow f as would already have been the case for any rightward veering of the boat. Thus, even before the course of the boat has deviated to an extent detectable by the wind-vane 1, any incipient veering by the boat causes the turbine 12-13 to effect an anticipated correction on the rudder 10. This ensures that after a disturbance, the deviation from course is reduced and the process of restoration to the steady-state is a damped one.

If the boat veers to the left, the gyroscopic precession moment due to the direction of rotation of the wheel 12 and to the operating sense of the coupling with the flap .18 will be exerted in the opposite direction to the arrow p. This causes the transmission link 17 to move upwardly and to deflect the flap 18 in the opposite direction to the arrow b, and this deflection tends to make the wind-vane 1 pivot in the opposite direction to the arrow f through the medium of the transmission between the wind-vane and the rudder 10, and causes the latter to be moved in the opposite direction to the arrow -F, that is to say in the direction tending to counter a leftward veering of the boat.

Reference is now had to FIG. 2 for a form of embodiment relevant to the case where the conventional sensing 3 wind-vane is replaced by a vane rotatable about an axis which is no longer vertical but near-horizontal, in accordance with the above-cited U.S. patent application. FIG. 2 refers to a situation in which nagivagation takes place with a following Wind V tending to maintain the vane or aerodynamic surface 19 aligned in its direction. Said aerodynamic surface is rigidly connected to an inclined hub 20 rotatably mounted in a support 21 adapted to swivel in a base 22 fixed to the boat deck. The hub 20 carries a lever 23 drivingly connected to a link 24 which is pivotally connected to one of the arms 25 of a lever 26 which is in turn pivotally connected to the base 22 and the other arm 27 of which is connected to the rudder 28 through a link 29.

If the boat veers to the right, the wind impinges upon the right-hand face of the vane 19, causing the latter to pivot in the direction of the arrow f and to thereby raise the link 24 which in turn moves the lever 26 in the direction of the arrow f and the rudder 23 in the direction of the arrow F, that is to say in the direction tending to counter the rightward veering of the boat.

In accordance with the present invention there is associated to this specific arrangement a rate gyro consisting of a wheel 39 equipped with blades'31 upon which the wind impinges frontally, say, instead of tangentially, thus causing the wheel 30 to rotate in the direction of the arrow r. The cradle 32 upon which this wind turbine 30-31 is rotatably mounted is pivotally supported on a shaft 33 which is carried in a support 34 rigidly connected to the hub 20 and which is downwardly oflset in such manner that the wheel 3% serve as a counterweight for the vane 19. The cradle 32 operates a link 35 which controls deflection of a flap 36 hinged to the trailing edge of the vane 19, the effect of which deflection is to modify the reactions of the wind on said vane.

With such an arrangement, the direction of rotation of the turbine 3031 and the operating sense of the coupling thereof with the wheel 19 are such that when the boat veers to the right for instance, the resulting gyroscopic precession moment on the wheel 30 rotating in the direction of the arrow r is exerted in the direction of the arrow p, thus causing a rearward movement of the link 35 and a deflection of the flap 36 in the direction of the arrow b. The effect of this deflection is to tilt the vane 19 in the direction of the arrow f as would already have been the case for any rightward veering of the boat. Thus even before any deviation from course detectable by the vane 19 can take place, any incipient veering of the boat will cause an anticipated correction to be applied to the rudder 28 through the agency of the turbine 30-31, whereby deviations from course are reduced and the process of restoration to the steady state is damped after any interference with the planned course.

Should the boat tend to veer to the left, the gyroscopic precession moment on the wheel 30 is exerted in the direction opposite to that of the arrow p, thus producing a forward movement of the link 35 and a deflection of the flap 36 in the opposite direction to the arrow b, which in turn tends to cause the vane 19 to tilt in the opposite direction to the arrow f Through the medium of the transmission link between the vane 19 and the rudder 28, the latter is deflected in the opposite direction to the arrow F, that is to say in the direction tending to counter the leftward veering of the boat.

It will be noted that neither FIG. 1 nor FIG. 2 includes mechanical means for restoring the rate gyro to its midway position; This is because it is possible to so proportion the flap 18 or 36 that its reactions to the wind be sufiicient to create the required restoring moment. Such and is more diflicult to, deflect. It may however be of advantage to fit a return spring of low strength in the linkage between the turbine 12-13 or 3i 31 and the flap 18 or 36 in order to return the mechanism to its neutral position when the wind force is low.

For greater clarity in the description of the underlying principle of the invention, the description given with reference to FIGS. 1 and 2 assumed navigation to be taking place with a following wind. It will, however, readily be appreciated that the present invention has for its object to permit of adjusting the gear, while sailing, for any rcla-- tive wind direction. In the specific instance of FIG. 1, all that is necessary is to move the pinion 7 away from the pinion 6 by any convenient means, whereby to other wise orientate the support 3 and the turbine 1213, and to then mesh these two pinions together once more. In the constructional form of FIG. 2, all that is necessary is to simply swivel the support 21 into the new direction, no preliminary disengagement of members being necessary in this case.

The present invention, though more particularly concerned with corrections made to the sensing and powergenerating surface of automatic boat steering gear, through the medium of an aerodynamic element and off a rate gyro type sensor, is not restricted to the case where the rate gyro wheel is driven by the relative wind, or where actuation of a trailing-edge trim flap is involved. The wind turbine may be replaced by an electric motor operating at constant speed, for instance. Likewise, the trailing edge flap may be replaced either by a leading edge flap 37 (FIG. 3), by spoilers 38 (FIG. 4) eXtendable from either side of the aerodynamic surface, or by a flap 39 which is hinged about a spar 40 (FIG. 5) positioned at its centre of pressure, in accordance with practices familiar enough to the aeronautical art to render any further description unnecessary.

Nor is the present invention by any means limited to the use of a coupling to the rudder helm for steering the boat. Alternatively, in accordance with a technique commonly used for operating boat or aircraft rudders, it would suifice merely to control a secondary flap 41 (FIG. 6) hinged to the trailing edge of the main piece of the rudder 42, the helm being left free to follow the motions caused by deflection of this flap.

Yet another alternative possibility would be to lock the rudder onto the desired navigating conditions and to operate only on an independent rudder 43 (FIG. 7).

Both of the last-mentioned techniques are sufiiciently well known for it to be unnecessary to give a specific description of their application to the present invention.

While there has been shown and described, the presently preferred embodiments of the improved automatic boat steering gear of this invention, it will be well understood by those skilled in the art that various changes and modifications may be made in these embodiments. It is, therefore, to be understood that the description hereinbefore set forth is not to be considered a limitation of the invention, but that changes may be made within the scope of the invention as set forth in the appended claims.

.What I claim is:

1. In a rate gyro type corrector for automatic boat steering gear of the kind comprising an aerodynamic surface which is connected to the submerged rudder of the boat and exposed to the wind, the. reactions of which thereon generate the sensing energy and motive power, said submerged rudder having a helm and a trailing edge, the improvement comprising, in combination, a rate gyro for sensing course deviations, a member for modifying the aerodynamic reaction of said aerodynamic surface exposed to the wind and means for controlling the posi tional relationship of said aerodynamic surface and said modifying member through said rate gyro and for generating a correction to said submerged rudder for any course deviation, through the resultant modification of comprises a trailing edge flap.

3. A rate gyro type corrector as said face exposed to the wind.

5. A rate gyro type corrector as claimed in claim 1, wherein said member for modifying the aerodynamic re- 6. A rate gyro corrector as claimed in claim 1, wherein said aerodynamic surface exposed to the wind is coupled to the helm of said submerged rudder.

7. A rate gyro type corrector as claimed in claim 1, comprising a secondary flap hinged tatable thereabout.

11. A rate gyro type corrector wherein said transmission of said subsecond pinion and a system connecting said shaft to the helm merged rudder.

13. A rate gyro type corrector as claimed comprising a first second pinion meshing with said first pinion,

second pinion, a secondary rudder and a transmission system connecting said shaft to said secondary rudder.

14. A rate gyro type corrector as claimed in claim 11, comprising a first pinion carried by said hollow hub, a second pinion meshing with said first pinion, a shaft rigidly connected to said second pinion, a secondary flap and a transmission system connecting said shaft to said seccradle to said member for modifying the aerodynamic reaction of said surface exposed to the wind.

References Cited by the Examiner UNITED STATES PATENTS 1,681,415 8/1928 Lee 114144 2,112,171 3/1938 Marlow 114-144 3, 180,298 4/1965 Gianoli 1 14-144 FOREIGN PATENTS 474,914 3/1915 France.

MILTON BUCHLER, Primary Examiner. ANDREW H. FARRELL, Examiner. 

1. IN A RATE GYRO TYPE CORRECTOR FOR AUTOMATIC BOAT STEERING GEAR OF THE KIND COMPRISING AN AERODYNAMIC SURFACE WHICH IS CONNECTED TO THE SUBMERGED RUDDER OF THE BOAT AND EXPOSED TO THE WIND, THE REACTIONS OF WHICH THEREON GENERATE THE SENSING ENERGY AND MOTIVE POWER, SAID SUBMERGED RUDDER HAVING A HELM AND A TRAILING EDGE, THE IMPROVEMENT COMPRISING, IN COMBINATION, A RATE GYRO FOR SENSING COURSE DEVIATIONS, A MEMBER FOR MODIFYING THE AERODYNAMIC REACTION OF SAID AERODYNAMIC SURFACE EXPOSED TO THE WIND AND MEANS FOR CONTROLLING THE POSITIONAL RELATIONSHIP OF SAID AERODYNAMIC SURFACE AND SAID MODIFYING MEMBER THROUGH SAID RATE GYRO AND FOR GENERATING A CORRECTION TO SAID SUBMERGED RUDDER FOR ANY COURSE DEVIATION, THROUGH THE RESULTANT MODIFICATION OF SAID AERODYNAMIC CHARACTERISTICS, WITH A REDUCED COURSE DEVIATION AND AN APERIODIC DAMPING. 